There is a need for effective pre-engagement detection of snipers because a single shot casualty of a high-value target is often sufficient to achieve the sniper's objective and there is often no intent to fire a second round. Pre-engagement detection of sniper weapons by detecting dispersion in radar signals after they interact with the rifle provides a proactive ability to eliminate or significantly reduce the threat of snipers by notifying the potential victim of presence of a sniper's weapon before the sniper shoots. What is needed is a technology capable of detecting snipers before they fire. Two methods are disclosed in this specification. A first apparatus and method is disclosed which differentiates between dispersive and non-dispersive radar signals to differentiate between cavities which are dispersive and clutter which is non-dispersive. A second apparatus and method is disclosed which processes a sequence of radar signals containing both dispersive and non-dispersive frequency components in such a way as to improve the signal-to-clutter ratio (SCR). This SCR enhanced signal can then be sent on to other processing apparatus for final detection.